Why do we associate fire with red...

...when it is mostly orange of various tones?

Same with the Sun, which is white and not yellow. But I suppose its because you can see it better at dusk.

Related question: why is candy with artificial raspberry flavoring invariably blue?

Because it heats things to a shade of red. Wood coals, charcoal, heated metal, all gain or emit a distinct red shade when at specific temperatures induced by flame.

We're the only primates with the ability to see red (If I remember correctly). Our ancestors would probably associate it with something good, like fire/heat.

Perhaps I was thinking of the greater primate family then? Hmm.

edited 5th Apr '11 7:22:51 PM by Ekuran

In your part of the world, maybe. They're invariably either mauve or deep red over here.

While fire itself is usually orange-ish, the burning of things that produce a lot of smoke (like, you know, wood and leaves and things we actually burned for a long time) as well as the red luminescence of heated objects due to blackbody radiation darken it into red hues.

edited 5th Apr '11 1:27:09 PM by Pykrete

You remember incorrectly, Ekuran. Most monkeys and apes have color vision comparable to ours, and that of the great apes is basically identical.

As to the OP, it's only in the last couple hundred years or so that "orange" has even been considered a separate color. Prior to that, people would have perceived fire as being a shade of red, especially in daylight.

edited 5th Apr '11 1:27:50 PM by Karalora

The sun looks yellow to me

The sun is also much, much hotter than most fires we can make.

Also keep in mind most terrestrial fire isn't purely blackbody radiation. You get a lot of additional coloring from ions in the thing being burned (most often trace sodium in the object's moisture, which produces a bright orange).

edited 5th Apr '11 1:45:02 PM by Pykrete

@Dead Mans - At dawn and dusk it is undeniably yellow, but at midday whatever yellow tones it has are pretty much absent. Although I think it is a matter of perspective, to you the midday sun still is somewhat yellow, to me it's whiteness actually fuses a bit with the blue sky, which makes sense as the blue skylight comes from the Sun.

Actually blue skylight has more to do with how particles in the air scatter blue light more sharply than other hues at midday angles of incidence. At sunrise/set you get a shallower angle of incidence and that changes refraction until red is the dominantly-scattered hue.

The sun isn't only yellow-white, but due to blackbody radiation at its particular temperature the dominant hue is yellowish.

edited 5th Apr '11 1:50:38 PM by Pykrete

So went out side, got a harsh reminder why we do not look up, and decided it still looks yellow.

There is no sun, and the sky is grey, not blue. I don't know what you guys are going on about.

Possibly related.

What Tom said. But flames are typically orange or yellow for generic combustion. Blue flames are way neato, and green flames are even cooler than that.

Anybody else feel like making a Fire Is Red trope?

Fire Is Red at least has a lot more basis in fact than Water Is Blue. At least fire can be red, and it makes things red. At least, I think that's where the association came from - red-hot metal, smoldering embers, etc.

I think part of the reason we associate fire with red is that, overall, humans in general dislike the color orange. I don't really have any proof for this, it's just something I heard in psychology, that we're "programmed" to naturally dislike orange.

As for the sun question, the sun IS a yellow star. If it were white, it'd have a different temperature, different size, and other different characteristics. It looks close to white with the naked eye from Earth at certain times, but using a telescope or other advanced methods can tell you that it's actually yellow.

Minor science detail - if I'm not mistaken, the colour of fire is due to line spectra, not blackbody radiation (the physics is somewhat related, but the observations are quite different). So comparing fire to the sun to explain its colour is not really a good idea.

For one thing, using Wien's displacement law to find the peak wavelength of the Sun's spectrum (taking its temperature as 5780K) shows it's about 500nm, i.e. in the visible range (although oddly, that's nearer to green than yellow. There's probably some explanation for why the Sun is considered a yellow star despite that...come to think of it, there's no "green star" classification, so maybe that's why). Anyway, surely it would be implausible to suggest that common fires, which are yellow/orange/maybe red, are at that kind of temperature (usually they're about 1000-2000K).

edited 6th Apr '11 11:59:05 PM by ashnazg

It's probably the Rayleigh scattering-the blue gets scattered out, the mix of red and green left behind seems yellow.

We say the Sun is yellow because of that so we say that any star of the same type is yellow.

edited 7th Apr '11 2:19:07 AM by SomeSortOfTroper